Vehicle fuel systems include evaporative emission control systems designed to reduce the release of fuel vapors to the atmosphere. For example, vaporized hydrocarbons (HCs) from a fuel tank may be stored in a fuel vapor canister packed with an adsorbent which adsorbs and stores the vapors. At a later time, when the engine is in operation, the evaporative emission control system allows the vapors to be purged into the engine intake manifold for use as fuel.
One example of such a fuel system in a hybrid vehicle is shown by Peters et al. in U.S. Pat. No. 9,709,006. Therein, a latchable refueling valve is held in an open position to enable vapor flow from the fuel tank to a vapor canister. Responsive to fuel tank pressure being higher than a threshold after the valve is held at the open position for a pre-determined duration, the latchable refueling valve is moved to an unlatched position.
However, the inventors herein have recognized that in a hybrid vehicle, the fuel vapors stored in the canister may primarily be refueling vapors. The fuel tank isolation valve isolates fuel vapors generated in the fuel tank from running loss and diurnal temperature cycles. These fuel vapors are therefore not be transferred into the fuel vapor canister and, instead, are contained within the fuel tank via the closed isolation valve. Accordingly, pressure may build in the fuel tank and a higher pressure may exist within the fuel tank. When the vehicle operator indicates a demand to refuel the hybrid vehicle, the fuel cap may remain locked until venting of the fuel tank is allowed to sufficiently reduce tank pressure. As such, the fuel cap is unlocked only after the tank pressure is below a threshold pressure, protecting the vehicle operator from being sprayed with fuel vapor. As a result, the vehicle operator, or a gas station attendant (or other “customer”), may have to wait for a time until the fuel tank is ready for refueling. This may result in customer anxiety and dissatisfaction. For example, the customer may be confused as to why the refueling door has not opened. In some cases, the customer may be unaware that depressurization is ongoing and may press a refueling button on the vehicle dash multiple times to confirm or expedite the refueling, causing controller errors. While some operators may learn an average wait time for a given vehicle over time, operators using a car-shared vehicle or an autonomous vehicle may not be aware of the wait time, adding to the confusion.
The inventors herein have recognized that providing a visual and/or auditory feedback to the vehicle operator after a refueling request is initiated may enable operator anxiety and dissatisfaction to be reduced. For example, providing a countdown to a time when the fuel tank is ready to receive the fuel may allow a refueling event to be better managed. The inventors have recognized that a display related to the refueling request may be advantageously provided to a vehicle operator or gas station attendant via existing vehicle puddle lights. In particular, motor vehicles may be configured with so-called puddle lights which illuminate the immediate surroundings of the vehicle in the dark when the vehicle is being entered or exited. These lights, also referred to in the art as “ambient lights”, can be mounted or inserted into the undersides of the door handles or exterior rear view (or side) mirrors so that they correspondingly illuminate the ground underneath. Frequently, these puddle lights are switched on when the doors are unlocked, for example by means of a remote key fob. By providing a display that is projected onto a ground surface via the puddle light, a vehicle operator and/or a gas station attendant may be updated of a time remaining until when the refueling can be performed. In one example, hybrid vehicle refueling is improved by a vehicle method comprising: responsive to a refueling request, estimating a time until a fuel tank is depressurized; and displaying the estimated time via a puddle light coupled to an exterior rear view mirror of the vehicle.
For example, in response to a refueling request, a vehicle controller may estimate a time required to depressurize the fuel tank. A countdown of the time remaining until the fuel tank is depressurized and ready to accept fuel is then displayed via the puddle lights onto a ground surface. For example, the countdown may be displayed on the ground outside a driver door. As another example, the countdown may be displayed on the ground outside a refueling door, which may be on the same side or the opposite side of the vehicle as the driver door. Further, a projection angle may be adjusted based on whether the driver is inside the vehicle or outside, as may be inferred from driver door angle. In addition to displaying the countdown with visual or animated cues, audible cues may be also be provided.
As a result, a vehicle operator and/or gas station attendant may be better appraised of a fuel tank depressurization progress during a refueling event. By providing a vehicle customer a real-time update regarding the progress of a fuel tank depressurization event, the customer may be better appraised of a time remaining before they can initiate refueling. By providing visual and/or audible cues, confusion and dissatisfaction for vehicle operators unfamiliar with the vehicle can be reduced, thereby averting premature opening of the fuel door. By acknowledging actuation of a refueling button and receipt of a refueling request via the visual and audible cues, repeated actuation of the refueling button by a vehicle operator is preempted. Overall, confusion related to refueling operations is reduced, and customer satisfaction is improved.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.